Method for mounting multishaft servo amplifier module

ABSTRACT

A thin-type multishaft servo-amplifier which has high resistance to vibration and shock and which can be installed in a narrow space and can be carried on a movable part of a machine is provided.  
     In a method for mounting a plurality of multishaft servo-amplifier modules, each of which has an identical shape and an identical function to each other and carries semiconductor power elements, on a multishaft servo-amplifier for driving motors, a plurality of multishaft servo-amplifier modules ( 1 ) through ( 6 ) are mounted on both the surfaces of a multishaft interface substrate ( 7 ) as a base plate in parallel with the surfaces of the substrate ( 7 ) to constitute a multishaft servo-amplifier function unit for a host controller.

TECHNICAL FIELD

The present invention relates to a method for mounting multishaftservo-amplifier modules on a multishaft servo-amplifier for drivingmotors used in an industrial machine.

BACKGROUND ART

Conventionally, for simultaneously controlling a plurality of motors bya host controller, the connection between the host controller and aservo-amplifier for driving respective shafts is electrically providedthrough bus connection, serial communication or the like using acommunication interface device which is connected to a transmissioncable (see Patent Reference No. 1, for example).

FIG. 9 is block diagram showing configuration examples of the multishaftservo-amplifier used in the above case. (a) shows Configuration Example1 and (b) shows Configuration Example 2 of the multishaftservo-amplifier. In FIGS. 9(a) and (b), reference number 83 designates ahost controller, reference numbers 84 designate communicationinterfaces, reference numbers 85 designate multishaft servo-amplifiermodules, reference number 86 designate servo-motors, reference number 87designates a transmission cable, reference number 88 designate busconnections or serial communication or the like, reference number 89designate motor cables, and reference number 90 designate a multishaftservo-amplifier function unit 90.

As illustrated in these figures, for controlling a plurality ofservo-amplifiers, the host controller 83 is typically connected to thecommunication interfaces 84 through the transmission cable 87. Thecommunication interfaces 84 are further connected to the multishaftservo-amplifier modules 85 through the bus connection, the serialcommunication or the like 88.

FIG. 9(a) shows the example where the communication interfaces 84 andthe servo-amplifier modules 85 are arranged with a one-to-onecorrespondence. FIG. 9(b) shows the example where one communicationinterface 84 is provided for the plural servo-amplifier modules 85 witha one-to-N (plural) correspondence.

In both of the examples, the plural multishaft servo-amplifier modulesare often collectively disposed in a side-by-side arrangement togetherwith the communication interface(s) for reasons of limitation to asupply line or the like of a power source and to wiring or for otherreasons.

An area boxed by a dotted line is the multishaft servo-amplifierfunction unit 90 including plural multishaft servo-amplifier modulesdisposed side by side. Each of the mutishaft servo-amplifier modules 85is connected to the corresponding servo-motor 86 through the motor cable89.

A typical mechanical method for providing a side-by-side arrangement ofthe multishaft servo-amplifier function unit 90 as the multishaftservo-amplifier involves a base-mounted type where the multishaftservo-amplifier modules are mounted on a base plate for installation, arack-mounted type where the multishaft servo-amplifier modules aremounted on a rack, and the like.

An example of the method for mounting the multishaft servo-amplifiermodules is described herein referring to the appended drawing. FIG. 10is an isometric drawing illustrating an example of an entire structureof a multishaft servo-amplifier on which base-mounted type multishaftservo-amplifier modules are mounted by a conventional method.

The multishaft servo-amplifier shown in the figure includes onecommunication interface and six multishaft servo-amplifier modules,thereby constituting a six-shaft servo-amplifier which controls sixservo-motors by the entire structure.

This multishaft servo-amplifier corresponds to the multishaftservo-amplifier function unit 90 shown in FIG. 9(b), where onecommunication interface 92 and six multishaft servo-amplifier modules 93are mounted on a base plate 91.

Each of the multishaft servo-amplifier modules 93 has a case 102, and aprinted board 103 which is equipped with semiconductor power elementsand electronic parts generally required for a servo-amplifier.

Connectors 96 and 97 disposed on each of the multishaft servo-amplifiermodules 93 electrically connects to a motor or an encoder, orelectrically supplies power, control signals, signal inputs/outputs,transmission and the like. The connectors 96 and 97 are mounted on theprinted board 103.

Connectors 94 and 95 disposed on the communication interface 92electrically supplies power, control signals, signal inputs/outputs,transmission and the like. The connectors 94 and 95 are connected withthe host controller through the transmission cable.

The communication interface 92 and the multishaft servo-amplifiermodules 93 are electrically connected to each other through busconnection, serial communication or the like, which is omitted in thefigure.

As for mechanical connections relating to the present invention, theprinted boards 103 of the six multishaft servo-amplifier modules 93 aremounted on the base plate 91, which has a sufficient area and strengthfor mounting the plural multishaft servo-amplifier modules 93, in suchpositions as to be disposed perpendicularly to the flat surface of thebase plate 91. Each of the multishaft servo-amplifier modules 93 isfixed to the base plate 91 by screws 101 having a length appropriate forfixation therebetween, which screws are inserted into two multishaftservo-amplifier module fixing plate upper holes and two multishaftservo-amplifier module fixing plate lower holes 100 provided on upperand lower multishaft servo-amplifier module fixing plates 99,respectively, and are inserted into four multishaft servo-amplifiermodule attachment screw taps 98 provided on the base plate 91 incorrespondence with the upper and lower holes 100.

As described above, in the conventional base-mounted typeservo-amplifier for a host controller, the plural multishaftservo-amplifier modules are mounted on the base plate perpendicularlythereto. These multishaft servo-modules simultaneously control thecorresponding plural servo-motors.

In recent years, there has been an increasing need for space-savinginstallation of a multishaft servo-amplifier. Furthermore, the number ofshafts tends to be increased due to enlarged functions in the field ofindustrial machinery including semiconductor manufacturing apparatussuch as a chip mounter. Additionally, the demand for mounting themultishaft servo-amplifier itself on a movable part of a machine hasbeen increasing for the reason of wiring-saving or other reasons.

Accordingly, it is preferable that the multishaft servo-amplifier usedin this field is not only small-sized and light-weight but also has highmechanical rigidity and a thin structure for increasing resistance tovibration and shock and for decreasing inertia generated at the time ofhigh-speed motion in the mechanical structure aspects.

In the conventional method, however, the servo-amplifier modules aremounted on the surface of the base plate perpendicularly thereto. As aresult, the depth of the multishaft servo-amplifier in the thicknessdirection of the base plate is large and it is thus impossible toinstall the multishaft servo-amplifier in a narrow space having a smalldepth.

Additionally, when the multishaft servo-amplifier is carried on amovable part of a machine, the entire thickness of the multishaftservo-amplifier is large for the carrying surface of the machine. Sincethe resistance to vibration and shock and the mechanical rigidity aredecreased due to the large thickness of the servo-amplifier, it isdifficult to mount the servo-amplifier on the movable part of themachine which is required to move at high speed.

DISCLOSURE OF THE INVENTION

Therefore, the invention is made for solving the above various problems,it is an object of the invention to provide a multishaft servo-amplifierwhich has a thin structure offering high resistance to vibration andshock, and which can be installed in a narrow space and can be carriedon a movable part of a machine, by mounting a plurality ofservo-amplifier modules on a surface of a base plate in paralleltherewith such that the entire thickness of the servo-amplifier can bereduced, and by efficiently mounting the servo-amplifier on bothsurfaces of the base plate.

For achieving the above object, the invention according to claim 1provides a method for mounting a plurality of multishaft servo-amplifiermodules on a multishaft servo-amplifier for driving motors, each ofwhich modules has an identical shape and an identical function to eachother and carries semiconductor power elements. In this method: amultishaft interface substrate as a base plate on which the pluralmultishaft servo-amplifier modules are mounted is provided to constitutea multishaft servo-amplifier function unit for a host controller; themultishaft servo-amplifier modules are mounted on the surface of themultishaft interface substrate in parallel therewith; and the multishaftservo-amplifier modules are mounted on both the surfaces of themultishaft interface substrate to efficiently mount the pluralmultishaft servo-amplifier modules on the multishaft interfacesubstrate.

In the invention according to claim 2, in the method for mountingmultishaft servo-amplifier modules of claim 1: connectors for connectingwith the multishaft interface substrate are disposed on diagonallyfacing areas of the multishaft servo-amplifier module, connectors forconnecting with the multishaft servo-amplifier module are disposed onboth the front and the rear surfaces of the multishaft interfacesubstrate in a zigzag arrangement, and the connectors for connectingwith the multishaft servo-amplifier module are alternately disposed onthe front and the rear surfaces of the multishaft interface substratesuch that the connectors for connecting with the multishaftservo-amplifier module do not interfere with each other; and themultishaft servo-amplifier modules are mounted on the same positions ofboth the surfaces of the multishaft interface substrate such that themultishaft interface substrate is sandwiched between each pair of themultishaft servo-amplifier modules, and the multishaft servo-amplifiermodules are mounted on the multishaft interface substrate in aside-by-side arrangement so as to efficiently mount the pluralmultishaft servo-amplifier modules on the multishaft interfacesubstrate.

In the invention according to claim 3, in the method for mountingmultishaft servo-amplifier modules of claim 1: through holes used forfixation are formed on the multishaft servo-amplifier modules to provideserially connected through holes formed by mounting the servo-amplifiermodules on the same positions of both the surfaces of the multishaftinterface substrate such that the multishaft interface substrate issandwiched between each pair of the multishaft servo-amplifier modules;and the multishaft servo-amplifier modules are fixed to the multishaftinterface substrate such that the multishaft interface substrate issandwiched between the pairs of the multishaft servo-amplifier modulesusing the serially connected through holes thus formed.

In the invention according to claim 4, in the method for mountingmultishaft servo-amplifier modules of any one of claims 1 to 3:attachment flat surfaces and structures having sufficient degrees offlatness and parallelism and strength are provided for the multishaftservo-amplifier modules such that the multishaft servo-amplifier can bedirectly attached to and carried on a movable part of a machine with adecreased entire thickness of the multishaft servo-amplifier for thecarrying surface of the movable part of the machine.

According to the methods of claims 1 through 3 as described above, it ispossible to mount the multishaft servo-amplifier modules on the flatsurface of the base plate in parallel therewith and to efficiently mountthe multishaft servo-amplifier modules on both the surfaces of the baseplate. Thus, a thin type multishaft servo-amplifier having a smallerheight in a thickness direction of the base plate than that of aconventional multishaft servo-amplifier is provided.

Therefore, a multishaft servo-amplifier which can be installed in anarrow space is provided.

Additionally, according to the methods of claims 1 to 4, a multishaftservo-amplifier having enhanced resistance to vibration and shock andincreased mechanical strength is provided since the thin type multishaftservo-amplifier can be carried on a carrying surface of a machine with adecreased entire thickness of the multishaft servo-amplifier for thecarrying surface of the machine. Thus, a multishaft servo-amplifierwhich can be carried on a movable part of a machine required to move athigh speed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view illustrating an example of an entirestructure of a multishaft servo-amplifier on which multishaftservo-amplifier modules are mounted by a method according to the presentinvention.

FIG. 2 illustrates the multishaft servo-amplifier module of theinvention, where (a) is a front view, (b) is a bottom view, (c) is aright side view and (d) is a back view of the multishaft servo-amplifiermodule.

FIG. 3 illustrates a multishaft interface substrate of the invention,where (a) is a front view (hidden lines indicated) and (b) is a bottomview of the multishaft interface substrate.

FIG. 4 is an exploded view of the multishaft servo-amplifier modulesshown in FIG. 2 and the multishaft interface substrate shown in FIG. 3.

FIG. 5 illustrates the multishaft servo-amplifier modules shown in FIG.2 and mounted on the multishaft interface substrate shown in FIG. 3,where (a) is a front view (hidden lines indicated) and (b) is a bottomview of the modules and substrate.

FIG. 6 is an isometric view of the multishaft servo-amplifier carried ona movable part of an industrial machine.

FIG. 7 shows attachment positions of the movable part of the industrialmachine to which the multishaft servo-amplifier is attached.

FIG. 8 illustrates attachment of the multishaft servo-amplifier to themovable part of the industrial machine in detail.

FIG. 9 is block diagram showing examples of a multishaftservo-amplifier, where (a) shows Configuration Example 1 and (b) showsConfiguration Example 2.

FIG. 10 is an isometric view illustrating an example of an entirestructure of a multishaft servo-amplifier on which base-mounted typemultishaft servo-amplifier modules are mounted by a conventional method.

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the present invention is herein described withreference to the appended drawings.

FIG. 1 is an isometric drawing illustrating an example of an entirestructure of a multishaft servo-amplifier on which multishaftservo-amplifier modules are mounted by a method according to the presentinvention.

In the figure, a multishaft servo-amplifier module unit (first shaft) 1for driving a motor is shown, which is a module of a servo-amplifierfunction unit for driving a motor and is equipped with semiconductorpower elements.

Second shaft through sixth shaft multishaft servo-amplifier module units2 through 6 each having a similar structure are also shown. Each of thesecond through sixth shaft module units 2 through 6 has a similar shapeand a similar function without any differences, but is distinguishedfrom each other by giving each module unit a reference numeralcorresponding to the shaft of the motor to be driven by the module unit.In this embodiment, these multishaft servo-amplifier modules 1 through 6are each mounted on a multishaft interface substrate 7 as a base plateby screws 8 and nuts 9 to constitute a six-shaft servo-amplifier in all.This is a servo-amplifier capable of controlling multiple shafts byconnecting a plurality of multishaft servo-amplifier modules to a hostcontroller. By using the multishaft servo modules, a plurality ofservo-motors corresponding to the modules are simultaneously controlled.

Next, the details of the invention are described in the order of thefigure numbers.

FIG. 2 illustrates the multishaft servo-amplifier module unit fordriving a motor, which carries semiconductor power elements. FIG. 2(a)is a front view, FIG. 2(b) is a bottom view, FIG. 2(c) is a right sideview, and FIG. 2(d) is a back view of the multishaft servo-amplifiermodule unit.

The multishaft servo-amplifier module chiefly includes a printed board10 and a pedestal 11. Connectors 12 and 13 for electrically supplyingpower and control signals to the multishaft interface substrate aremounted on the printed board 10. These connectors 12 and 13 are disposedin areas 12 a and 13 a, respectively, which are diagonally positioned onthe printed board 10 partitioned by a center line (vertical line) 21 anda center line (horizontal line) 22 in the front view of the multishaftservo-amplifier module shown in FIG. 2(a). That is, the connector 12 andthe connector 13 are located in the areas diagonally facing to eachother in the front view of the multishaft servo-amplifier module.

Moreover, connectors 14 and 15 for supplying power and control signalsto a motor for driving a machine or an encoder, and electronic partsgenerally required for the servo-amplifier as well as the semiconductorpower elements are carried on the printed board 10.

The pedestal 11 is constituted by four pedestal legs 16 through 19 andan attachment flat surface 20 also functioning as an attachment surfaceto a machine. The pedestal 11 is preferably made from a material whichhas large mechanical strength and is light-weight considering that thepedestal 11 is carried on a movable part of a machine. In thisembodiment, the pedestal 11 is made from integrally formed aluminummaterial.

The pedestal legs 16 through 19 have through holes 16 a through 19 a,respectively, which are provided to position and fix the multishaftservo-amplifier module, in the vertical direction in the front view ofthe multishaft servo-amplifier module.

The printed board 10 and the pedestal 11 are in correspondence with andrigidly fixed to each other. For example, a plurality of holes forscrews are formed on the printed board 10, and female screw taps forthose screws in the same number as that of the holes of the printedboard 10 are formed on the pedestal 11. This structure allows theprinted board 10 to be rigidly fixed to the pedestal 11.

FIG. 3 illustrates a multishaft interface substrate unit alsofunctioning as the base plate on which the plural servo-amplifiermodules are mounted to constitute the multishaft servo-amplifierfunction unit for the host controller. FIG. 3(a) is a front view (hiddenlines indicated) and FIG. 3(b) is a bottom view of the multishaftinterface substrate unit.

In this embodiment, the multishaft interface substrate 7 is a base platesubstrate on which six multishaft servo-amplifier modules are mounted toconstitute a servo-amplifier capable of driving six motors.

The multishaf interface substrate 7 has connectors for electricallysupplying power and control signals to the servo-amplifier modules. Theconnectors are disposed on both surfaces of the substrate 7 in a zigzagarrangement, and are alternately positioned on each side of thesubstrate 7.

More specifically, connectors 23 and 24 are connectors whichelectrically connects to the multishaft servo-amplifier module 1 (firstshaft) and are carried on the front surface of the multishaft interfacesubstrate 7. Connectors 23 a and 24 a are connectors which electricallyconnects to the multishaft servo-amplifier module 2 (second shaft) andare carried on the rear surface of the multishaft interface substrate 7.

Similarly, connectors 25 and 26 are connectors which electricallyconnect to the multishaft servo-amplifier module 3 (third shaft) and arecarried on the front surface of the multishaft interface substrate 7.Connectors 25 a and 26 a are connectors which electrically connect tothe multishaft servo-amplifier module 4 (fourth shaft) and are carriedon the rear surface of the multishaft interface substrate 7.

Similarly, connectors 27 and 28 are connectors which electricallyconnect to the multishaft servo-amplifier module 5 (fifth shaft) and arecarried on the front surface of the multishaft interface substrate 7.Connectors 27 a and 28 a are connectors which electrically connect tothe multishaft servo-amplifier module 6 (sixth shaft) and are carried onthe rear surface of the multishaft interface substrate 7.

Thus, the connectors 23 through 28 and the connectors 23 a through 28 aare disposed on the front surface and the rear surface, respectively, ofthe multishaft interface substrate 7 in a zigzag arrangement and arealternately positioned such that each of the connectors on the front andthe rear surfaces does not interfere with the connector on the oppositeside.

The connectors 23 and 24 are arranged in correspondence with theconnectors 12 and 13 provided on the multishaft servo-amplifier module 1(first shaft) for connection with the multishaft interface substratewith the same pitch as that of the connectors 12 and 13. Similarly, theconnectors 25 and 26, 27 and 28, 23 a and 24 a, 25 a and 26 a, and 27 aand 28 a are positioned with the same pitch.

Furthermore, the multishaft interface substrate 7 carries acommunication interface function unit for providing transmission for thehost controller, connectors 29 through 32 for supplying power to theamplifier, and connectors for electrically supplying control signals,signal inputs and outputs, transmission and the like from the hostcontroller.

The multishaft interface substrate 7 also carries ectronic partsrequired for constituting the entire multishaft servo-amplifier on whichthe multishaft servo-amplifier modules are mounted, but such electricparts are omitted in the figure.

Holes 33 through 36 for positioning and fixing the multishaftservo-amplifier modules are shown in the figure. In this embodiment, theholes 33 through 36 correspond to both the multishaft servo-amplifiermodule 1 (first shaft) and the multishaft servo-amplifier module 2(second shaft), and simultaneously fix these two multishaftservo-amplifier modules.

Similarly, holes 37 through 40 are provided for positioning and fixingboth the multishaft servo-amplifier module 3 (third shaft) and themultishaft servo-amplifier module 4 (fourth shaft), and holes 41 through44 are provided for positioning and fixing both the multishaftservo-amplifier module 5 (fifth shaft) and the multishaftservo-amplifier module 6 (sixth shaft).

FIG. 4 is an exploded view of the multishaft servo-amplifier modulesshown in FIG. 2 and the multishaft interface substrate shown in FIG. 3.In this figure, only the multishaft servo-amplifier module 5 (fifthshaft) and the multishaft servo-amplifier module 6 (sixth shaft) areillustrated as a disassembly example.

FIG. 5 illustrates the six multishaft servo-amplifier modules shown inFIG. 2 which are mounted on the multishaft interface substrate shown inFIG. 3. FIG. 5(a) is a front view (hidden lines indicated) and FIG. 5(b)is a bottom view of the servo-amplifier modules.

Next, a method for mounting the two multishaft servo-amplifier modules 5(fifth shaft) and 6 (sixth shaft) on the multishaft interface substrate7 also functioning as the base plate is sequentially described.

The connectors 12 and 13 (both shown in FIG. 2) carried on themultishaft servo-amplifier module 5 (fifth shaft) for connection withthe multishaft interface substrate are brought into engagement with theconnectors 27 and 28 (both shown in FIG. 3), respectively, carried onthe front surface of the multishaft interface substrate 7 for connectionwith the multishaft servo-amplifier module.

Connector engagement positions 49 and 50 are shown in FIG. 5(a).Similarly, the connectors 12 and 13 carried on the multishaftservo-amplifier module 6 (sixth shaft), which connectors have a shapeand a function identical to those on the multishaft servo-amplifiermodule 5, for connection with the multishaft interface substrate arebrought into engagement with the connectors 27 a and 28 a, respectively,carried on the rear surface of the multishaft interface substrate 7 forconnection with the multishaft servo-amplifier module.

Connector engagement positions 49 a and 50 a are shown in FIG. 5(a). Inthis arrangement, the connectors 12 and 13 for the connection with themultishaft interface substrate are disposed on diagonally facing areasof the multishaft servo-amplifier module, and simultaneously theconnectors for connection with the multishaft servo-amplifier module aredisposed on both the front and the rear surfaces of the multishaftinterface substrate 7 in a zigzag arrangement and are alternatelypositioned such that the connectors provided on the front and rearsurfaces of the multishaft interface substrate 7 for connection with themultishaft servo-amplifier module do not interfere with each other.Thus, for mounting the multishaft servo-amplifier modules on themultishaft interface substrate 7, the substrate 7 is sandwiched betweenthe pairs of the multishaft servo-amplifier modules which are located atthe same positions of the opposite surfaces. In this structure, theprinted board 10 of each servo-amplifier module is mounted on the flatsurface of the multishaft interface substrate 7 in parallel therewith.

Described next is a method for fixing these two multishaftservo-amplifier modules which have been mounted on both the surfaces ofthe multishaft interface substrate in parallel therewith under theabove-described condition.

As illustrated in FIG. 4, the though hole 16 a for positioning andfixing the multishaft servo-amplifier module 5 (fifth shaft) is formedin the pedestal 16 which is disposed at one of the four corners of themultishaft servo-amplifier module 5 (fifth shaft). Similarly, thethrough hole 18 a for positioning and fixing the multishaftservo-amplifier module 6 (sixth shaft) is formed in the pedestal 18 ofthe multishaft servo-amplifier module 6 (sixth shaft). Also, the hole 44for positioning and fixing the multishaft servo-amplifier modules isprovided on the multishaft interface substrate 7.

When the multishaft servo-amplifier 5 (fifth shaft) and the multishaftservo-amplifier 6 (sixth shaft) are mounted on the multishaft interfacesubstrate 7, the through holes 18 a, the hole 44 and the through hole 16a are connected. That is, a serially connected through hole is formed bymounting the pair of the multishaft servo-amplifier modules such thatthe multishaft interface substrate is sandwiched by the modules. Byusing the screw 8 having a sufficient length to be inserted into thethrough hole thus formed and the nut 9 fitting with the screw 8, the twomultishaft servo-amplifier modules can be fixed to the multishaftinterface substrate such that the interface substrate is sandwichedbetween the two servo-amplifier modules. The remaining three positionsof the four corners are fixed by inserting the screws into seriallyconnected through holes thus formed and by attaching the nuts in thesame manner.

The method for mounting the multishaft servo-amplifier module 5 (fifthshaft) and the multishaft servo-amplifier module 6 (sixth shaft) on themultishaft interface substrate and for fixing those servo-amplifiermodules 5 and 6 to the interface substrate such that the interfacesubstrate is sandwiched between the servo-amplifier modules 5 and 6 asdescribed above is applied to the pair of the multishaft servo-amplifiermodule 1 (first shaft) and the multishaft servo-amplifier module 2(second shaft) and to the pair of the multishaft servo-amplifier module3 (third shaft) and the multishaft servo-amplifier module 4 (fourthshaft). The six servo-amplifier modules in all are thus mounted on themultishaft interface substrate in a side-by-side arrangement, therebyconstituting a six-shaft servo-amplifier.

By mounting the multishaft servo-amplifier modules on the flat surfaceof the base plate in parallel therewith, a thin type multishaftservo-amplifier having a smaller height in the thickness direction ofthe base plate than the conventional multishaft servo-amplifier can beprovided.

When the multishaft servo-amplifier modules are mounted on the flatsurface of the base plate in parallel therewith, the mounting efficiencywill be deteriorated since such a structure requires a large area formounting the servo-amplifier modules. However, for overcoming thisdrawback, the servo-amplifier modules are mounted on both the surfacesof the base plate in this embodiment, which allows the mounting area tobe increased and the mounting efficiency to be enhanced.

Next, a method for attaching the multishaft servo-amplifier to anindustrial machine is described referring to a chip mounter forautomatically mounting electronic parts and the like on the printedboard as an example.

FIG. 6 is an isometric view of the multishaft servo-amplifier carried ona movable part of a chip mounter. The chip mounter includes a mountertable 51 and a mounter head 52. The mounter head 52 moves the mountertable 51 in a horizontal direction or a vertical direction. Anattachment flat surface 66 of the mounter head 52 is made from metalsuch as aluminum which has sufficient mechanical strength and degrees offlatness and parallelism for directly carrying a multishaftservo-amplifier 53.

As illustrated in FIG. 7, screw taps used for mounting the multishaftservo-amplifier are prepared on the attachment flat surface 66 of themounter head.

A flat surface region 67 encompassed by four screw taps 54 through 57used for attaching the multishaft servo-amplifier corresponds to a flatsurface to which the multishaft servo-amplifier module 2 (second shaft)is attached.

Similarly, a flat surface region 68 encompassed by four screw taps 58through 61 used for attaching the multishaft servo-amplifier correspondsto a flat surface to which the multishaft servo-amplifier module 4(fourth shaft) is attached.

Similarly, a flat surface region 69 encompassed by four screw taps 62through 65 used for attaching the multishaft servo-amplifier correspondsto a flat surface to which the multishaft servo-amplifier module 6(sixth shaft) is attached.

The attachment flat surfaces 66 through 68 have sufficient mechanicalstrength, degrees of flatness and parallelism, and a hole depth fordirectly carrying the multishaft servo-amplifier 53.

FIG. 8 illustrates attachment of the multishaft servo-amplifier to themounter head 52 (a movable part of a machine). Each of the multishaftservo-amplifier module 2 (second shaft), the multishaft servo-amplifiermodule 4 (fourth shaft), and the multishaft servo-amplifier module 6(sixth shaft) has the pedestal attachment flat surface 20 for attachmentto a machine at the pedestal of the multishaft servo-amplifier module(see FIG. 2). The flat surface 20 also has sufficient mechanicalstrength and degrees of flatness and parallelism for attachment to themovable part of the machine.

The pedestal attachment flat surface 20 of the second multishaftservo-amplifier module 2 (second shaft) for attachment to a machine isbrought into surface contact with the flat surface 67 of the chipmounter for attachment to the multishaft servo-amplifier module, suchthat hole positions 71 through 74 for fixing the multishaftservo-amplifier module 1 (first shaft) and the multishaftservo-amplifier module 2 (second shaft) to the multishaft interfacesubstrate 7 shown in FIG. 5 are aligned with the screw taps 54 through57 for attaching the mutishaft servo-amplifier shown in FIG. 7.

Under this condition, as shown in FIG. 8, by inserting screws 70 forfixing the multishaft servo-amplifier into the holes provided in thepedestal legs of the multishaft servo-amplifier modules, the multishaftservo-amplifier modules attached to the multishaft interface substratecan be screw-fixed at four positions of the screw taps 54 through 57provided on the chip mounter for attaching the multishaftservo-amplifier.

Similarly, the pedestal attachment flat surface 20 of the multishaftservo-amplifier module 4 (fourth shaft) for attachment to a machine ispositioned with respect to the screw taps 58 through 61 for attachingthe multishaft servo-amplifier in surface contact between the pedestalattachment flat surface 20 and the flat surface 68 of the chip mounterfor attachment to the multishaft servo-amplifier module. Also, thepedestal attachment flat surface 20 of the multishaft servo-amplifiermodule 6 (sixth shaft) for attachment to a machine is positioned withrespect to the screw taps 62 through 65 for attaching the multishaftservo-amplifier in surface contact between the pedestal attachment flatsurface 20 and the flat surface 69 of the chip mounter for attachment tothe multishaft servo-amplifier module.

The multishaft servo-amplifier modules 4 (fourth shaft) and themultishaft servo-amplifier modules 6 (sixth shaft) are furtherscrew-fixed to the screw taps 58 through 61 and 62 through 65 providedon the chip mounter for attaching the multishaft servo-amplifier,respectively, by the screws 70 for fixing the multishaftservo-amplifier.

Since the servo-amplifier modules themselves are provided with theattachment flat surfaces and the structure having sufficient degrees offlatness and parallelism as described above, the thin-type multishaftservo-amplifier can be directly attached onto a movable part of amachine including semiconductor manufacturing apparatus such as a chipmounter.

As described above, the thin type multishaft servo-amplifier can beattached such that its entire thickness for a carrying surface of amachine is decreased. With the decreased entire thickness of theservo-amplifier for a carrying surface of a machine, resistance tovibration and shock and mechanical rigidity of the amplifier areincreased due to the small thickness and thus the amplifier can becarried on a movable part of a machine required to move at high speed.

While the six-shaft servo-amplifier is shown in this embodiment, themultishaft interface substrate for six shafts may mount one up to sixmultishaft servo-amplifier modules as a modified embodiment. In theabove description, the multishaft servo-amplifier modules are mounted atthe same positions of both the surfaces of the multishaft interfacesubstrate such that the interface substrate is sandwiched between thepairs of the servo-amplifier modules for fixing the servo-amplifiermodules to the substrate. However, such a structure may be adopted inwhich the multishaft servo-amplifier modules are mounted on either thefront or the rear surface of the multishaft interface substrate and themultishaft servo-amplifier modules are fixed to the multishaft interfacesubstrate using screws having sufficient length for fixing the modulesto the substrate and nuts fitting with the screws. That is, it ispossible to freely select the shaft number of the multishaftservo-amplifier modules from one to six as long as it is within themaximum shaft number.

In another modified embodiment, the shaft number can be more freelyselected by employing a multishaft interface substrate capable ofmounting 8-shaft, 10-shaft, 12-shaft or larger shaft number multishaftservo-amplifier modules. That is, a multishaft servo-amplifier for anynumber of shafts which is applicable to various purposes of use withflexibility can be provided by preparing multishaft interface substratesfor a single up to plural shafts.

In still another modified embodiment, the arrangement of the multishaftservo-amplifier modules is not limited to a linear and side-by-sidearrangement as in this embodiment. In the embodiment described herein,the pair of the multishaft servo-amplifier module 1 (first shaft) andthe multishaft servo-amplifier module 2 (second shaft), the pair of themultishaft servo-amplifier module 3 (third shaft) and the multishaftservo-amplifier module 4 (fourth shaft), and the pair of the multishaftservo-amplifier module 5 (fifth shaft) and the multishaftservo-amplifier module 6 (sixth shaft) are linearly disposed adjacent toeach other as shown in FIG. 5(a). It is possible, however, to mount themultishaft servo-amplifier modules on any positions of the multishaftinterface substrate other than in the linear arrangement as long as thepair of the multishaft servo-amplifier modules are mounted such that onemodule is on the same position of one surface of the multishaftinterface substrate and the other module is on the same position of theother surface of the interface substrate and as long as the interfacesubstrate is sandwiched between the pair of the modules for fixing themodules thereto. Thus, a multishaft servo-amplifier which is applicableto any shapes in accordance with purposes of use with flexibility can beprovided.

INDUSTRIAL APPLICABILITY

The present invention is applicable to a method for mounting multishaftservo-amplifier modules on a multishaft servo-amplifier for drivingmotors used especially for an industrial machine so as to provide a thinamplifier structure having high resistance to vibration and shock. Theinvention is thus utilized in a field of manufacturing and providing themultishaft servo-amplifier which can be installed in a narrow space andcan be carried on a movable part of a machine.

1. A method for mounting a plurality of servo-amplifier modules fordriving motors on a multishaft servo-amplifier, each of the plurality ofservo-amplifier modules includes an identical shape and an identicalfunction to each other and has semiconductor power elements, comprising:preparing a multishaft interface substrate, that constitutes amultishaft servo-amplifier function unit for a host controller, as abase plate on which the plurality of multishaft servo-amplifier modulesare mounted; mounting the multishaft servo-amplifier modules on surfacesof the multishaft interface substrate in parallel therewith; andmounting the multishaft servo-amplifier modules on the both surfaces ofthe multishaft interface substrate to efficiently mount the pluralmultishaft servo-amplifier modules on the multishaft interfacesubstrate.
 2. The method for mounting a plurality multishaftservo-amplifier modules according to claim 1, further comprising:disposing connectors for connecting with the multishaft interfacesubstrate on diagonally facing areas of the multishaft servo-amplifiermodule, disposing connectors for connecting with the multishaftservo-amplifier module on the both front and rear surfaces of themultishaft interface substrate in a zigzag arrangement, and disposingthe plurality of the multishaft servo-amplifier modules alternately onthe front and the rear surfaces of the multishaft interface substratesuch that the connectors for connecting with the multishaftservo-amplifier module do not interfere with each other; and mountingthe multishaft servo-amplifier modules on the same positions of the bothsurfaces of the multishaft interface substrate such that the multishaftinterface substrate is sandwiched between each pair of the multishaftservo-amplifier modules, and mounting the multishaft servo-amplifiermodules on the multishaft interface substrate in a side-by-sidearrangement so as to efficiently mount the plural multishaftservo-amplifier modules on the multishaft interface substrate.
 3. Themethod for mounting a plurality multishaft servo-amplifier modulesaccording to claim 1, further comprising: forming through holes used forfixation on the multishaft servo-amplifier modules to provide seriallyconnected through holes formed by mounting the servo-amplifier moduleson the same positions of the both surfaces of the multishaft interfacesubstrate such that the multishaft interface substrate is sandwichedbetween each pair of the multishaft servo-amplifier modules; and fixingthe multishaft servo-amplifier modules to the multishaft interfacesubstrate such that the multishaft interface substrate is sandwichedbetween the pairs of the multishaft servo-amplifier modules using theserially connected through holes thus formed.
 4. The method for mountinga plurality multishaft servo-amplifier modules according to any one ofclaims 1 to 3, further comprising: providing attachment flat surfacesand structures having sufficient degrees of flatness and parallelism andstrength for the multishaft servo-amplifier modules such that themultishaft servo-amplifier can be directly attached to and carried on amovable part of a machine with a decreased entire thickness of themultishaft servo-amplifier for the carrying surface of the movable partof the machine.
 5. A multishaft servo-amplifier comprising: a multishaftinterface substrate; and a plurality of servo-amplifier modules, each ofthe plurality of servo-amplifier modules includes semiconductor powerelements and drives a motor, wherein the plurality of multishaftservo-amplifier modules are mounted on front and rear surfaces of themultishaft interface substrate.
 6. The multishaft servo-amplifieraccording to claim 5, further comprising: connectors for connecting withthe multishaft interface substrate, disposed on diagonally facing areasof the each of the plurality of servo-amplifier modules; and connectors,for connecting with the plurality of multishaft servo-amplifier modules,disposed on both front and rear surfaces of the multishaft interfacesubstrate in a zigzag arrangement, wherein ones of the plurality of themultishaft servo-amplifier modules are disposed on a front surface ofthe multishaft interface substrate in a side-by-side arrangement, andanothers of the plurality of the multishaft servo-amplifier modules aredisposed on a rear surface of the multishaft interface substrate in aside-by-side arrangement, each positions where the ones of the pluralityof the multishaft servo-amplifier are mounted on the front surfacecorresponds to each positions where the anothers of the plurality of themultishaft servo-amplifier are mounted on the rear surface, such thatthe multishaft interface substrate is sandwiched between each pair ofthe multishaft servo-amplifier modules, and each positions of theconnectors on the front surface does not corresponds to each positionsof the connectors on the rear surface.
 7. The multishaft servo-amplifieraccording to claim 5, further comprising: through holes formed on eachof the plurality of servo-amplifier modules; and holes formed on themultishaft interface substrate, wherein one of the through holes of oneof the servo-amplifier modules mounted on the front surface, another ofthe through holes of another of the the servo-amplifier modules mountedon the rear surface and one of holes on the multishaft interfacesubstrate constitute a serially connected through hole.